I liked the idea of developing and testing with your own "schema" before cutting across to a dbo implementation.

It is not a facility that I commonly use and I don't know many other people who do. The problem is that if you work in a shop where no-one else uses a facility then who do you learn what the correct use of that facility is?

There are two uses for this facility that spring to mind.

1. Holding personalised settings for an app a'la windows profiles.

2. A centrally managed app where the data and/or other objects have to be isolated according to the user.

These days the sort of isolation and security that is carried out at the application level rather than the database level.

In the case of point 2 its a case of "an" answer rather than "the" answer.